Troubleshooting Mountain Lion

Good news. Based on reviews I’ve read (and my own experience), the consensus appears to be that OS X Mountain Lion is a generally stable update with a minimum of significant problems, especially for a 10.x.0 release. Still, things can and do occasionally go wrong. It always pays to be cautious before upgrading to a new version of OS X. This remains true for Apple’s latest cat.

I’ll highlight one general install tip here: After downloading the Install OS X Mountain Lion app from the Mac App Store, you’ll find it in your Applications folder. Make a copy of the app before proceeding. Otherwise, the app will vanish without a trace after you complete the install (this is a deliberate feature, not a bug). Yes, you can get it back by re-downloading the app, but keeping a copy saves you time and hassle, in case you ever want to use Install again.

After you have Mountain Lion up and running, you are still not home free. Here’s a round-up of some post-install Mountain Lion problems you may encounter:

Migration Assistant failure

If you try to use Migration Assistant to migrate to Mountain Lion, you may find that the Assistant app crashes. Don’t worry you can still get things working. As Apple explains, all you need to do is uncheck the Back to My Mac item in iCloud System Preferences on the destination Mac. The migration should now succeed. When you’re done, you can re-enable Back to My Mac.

Login trouble

According to Apple, “After upgrading to OS X Mountain Lion, your Mac may keep returning to the login window after you have logged in.” This is clearly something you’ll want to fix ASAP.

The most likely culprit is an incompatible Login Item. OS X makes an effort to automatically disable incompatible software on startup. Apparently, some apps may still sneak in under the fence. The solution is to reboot your Mac in Safe Mode (by holding down the Shift key until the grey Apple logo appears). This prevents your Login Items from loading. Now go to System Preferences -> Users & Groups> -> Login Items. Look for any item that “has a prohibitory sign (a grey circle with a slash) over its icon.” This indicates an incompatible item. Delete any such items and restart your Mac normally. All should now be well.

No Wi-Fi after waking from sleep

Numerous users report that, after waking their Mountain-Lion-upgraded Mac from sleep, the Mac does not automatically re-connect to the local Wi-Fi network. Making matters worse, attempts to manually reconnect may lead to a persistent spinning beachball, making reconnection just about impossible.

A solution that has worked for at least some users is to:

Go to Network System Preferences and click the Advanced button;

From the Wi-Fi tab, delete all the known networks

Return to the main Network display and delete Wi-Fi from the Services list.

Finally, add a new Wi-Fi service (by clicking the + icon at the bottom of the list section).

Unfortunately, this is not a sure-fire fix. Many users with this symptom continue to struggle to find a cure. A few suggest that incompatible third-party software is the root case. A few have found that turning off Bluetooth eliminates the symptom.

Bluetooth-related kernel panic after wake from sleep

Speaking of Bluetooth, Avatron Software’s blog reports that if you turn off Bluetooth-connected devices while your Mac is asleep, a kernel panic may occur when you wake up the Mac. If you’ve additionally disabled “Allow Bluetooth devices to wake this computer,” located in the Advanced section of Bluetooth System Preferences, the kernel panic may occur even if you leave the Bluetooth devices on. Avatron believes the cause is a bug that Apple will likely fix in 10.8.1.

Mail replies from wrong address

As reported by Kirk McElhearn (who cites an Apple Support Communities thread on the matter), the new version of Mail in Mountain Lion has trouble assigning the correct address for email replies. If you have multiple email accounts, when you select to reply to an email, Mail should use the account that received the message as your “from” address. This should override any selection you have made for a default address to use with new messages. That’s the way things worked in Lion.

The problem is that Mail may now instead use your default address for replies, ignoring when the received message comes from a different account. Postings in the Apple thread offer some potential workarounds, but not any outright fix. On the other hand, you may not see this symptom at all. When I tried to replicate it, I could not do so; I always got the “account matching” email address when selecting to reply.

4 Comments

I would like to understand if someone has experienced a problem with Mail after downloading mountain lion especially with sending and receiving mail after waking the computer from sleep mode. There appears to be no problem if you turn the computer off and on again

I too have a problem with Mail after waking up. Mail seems to disconnect and both my email account are ‘offline’. When I select ‘put online’ it says they cannot be connected. I can close mail then open again, and it works fine. Any ideas?

The problem described by Aubrey is common. I have this problem and know of others with it also. Similarly, PhotoStream in iPhoto goes offline after waking up from sleep. As with Mail, quitting and restarting each fixes it, but this is sub-standard and should be properly recognised and resolved by Apple.

“The problem is that Mail may now instead use your default address for replies, ignoring when the received message comes from a different account. Postings in the Apple thread offer some potential workarounds, but not any outright fix. On the other hand, you may not see this symptom at all. When I tried to replicate it, I could not do so; I always got the “account matching” email address when selecting to reply.” If you sort your mail using rules so that messages go into folders On My Mac as soon as they are received, when you reply Mail defaults to an address that isn’t the one the message was sent to. If the message says in the inbox it’s not a problem. It only happens if you sort on receipt. Very annoying. I’ve given up and am using Postbox.